Ammunition propellant



Feb. 7, 1961 D. w. RYKER 2,970,899

AMMUNITION PROPELLANT Filed sept. 28, 1955 s sheets-sheet 1cARBoHYDRAzlDE- NITRIC ACID-WATER SYSTEM AAVAVAV VAYA VAVAVAVAVAVAVAVA NH 2 N H\ 9:0 loo/ v v HNO3 NHZNH MoNoNlTRATE K DINITRATE '00A H 2 O|007., A SEMICARBAZIDE- NITRIC ACID WATER SYSTEM FIGURE 2AVAVAVAVAVAVAVAVAVAVA AVAVAVAVAVAVAVAVAVAVAVA AVAVAVAVAVAVAVAVAVAVAVAVAAvAVAVAVAVAVAVAVAVAVAVAVAVA VAVAVAVAVAVAVAVAVAVAVAVAVAVAAVAVAVAVAVAVAVAVAVAVAVAVAVAVAVA AVAVAVAVAVAVAVAVAVAYAVAVAVAVAVA N H 2 NH\ AVAVAVAVAVAVAVAAVAVAVAVAVAVAVAVAVA 9: o H N O 3 NH2 O04 MoNoN|TRATE-\DINITRATE O04 l CC CHARGES INVENToR. e N0 F|RE DON W.RYKER FIRINGRESULTS ATT R NEY CHAMBER PRESSURE (LBS./SQ.IN.X IO) Feb. 7, 1961 FiledSept. 28, 1955 3 Sheets-Sheet 2 EFFECT OF CHARGE VOLUME ON CHAMBERPRESSURE IOO CHARGE VOLUME (cc) f vs -2 CHAMBEF PRES SU RE(LBS./SQ.|N.XIO)

CHARGE VOLUME (CC) FIGURE 3 INVENTOR. DoN w.RYKl-:R

ATToNEY D. W. RYKER AMMUNITION PROPELLANT Feb. 7, l1961 Filed Sept. 28,1955 OOO OOO N OOOm (oas/ld) imo-ISA lA/vToR. DON. W ./RYKER W RNEY2,970,899 AMMUNITIN PROPELLANT Don W. Ryker, Woodbridge, Conn., assignorto Olin Mathieson Chemical Corporation, New Haven, Conn., a corporationof Virginia Filed Sept. 28, 1955, Ser. No. 537,151

c6 Claims. (Cl. 52-1) This invention relates to a propellant and moreparticularly to a liquid propellant.

The recent trend in propellants for use in the ammunition iield has beendirected toward those of the liquid type. Liquid propellants are favoredbecause they are easy to store, do not require grain formation, areeasily loaded and dispensed and can be used in such manner to utilizesubstantially all of their potential. There are many known liquidpropellants. However all of these are not useful for use in ammunitionbecause they are either unstable, sensitive, brisant, too slow or toofast burning or of an undesirable low or high potential.

. An object of this invention is to provide a novel class of liquidpropellants. Another object of this invention is to provide a method formaking this novel class of liquid propellants. A further object of thisinvention is to provide compositions utilizing this novel class ofliquid propellants useful for ammunition. And a further object of thisinvention is to provide liquid propellant compositions that are stable,insensitive `and slow burning. Other objects will become apparent tothose skilled in the art upon reading the following detailed disclosureand description, with accompanying drawings in which j Figure 1 is agraph illustrating the desirable range of mixtures ofcarbohydrazide-nitric acid-water particularly useful as propellants.

Figure 2 is a graph showing the desirable range of mixtures ofsemicarbazide-nitric acid-water particularly useful as propellants.

Figure 3 is a graph showing the effect of charge volume of thecarbohydrazide nitrate of Figure 1 on chamber pressure, and

Figure 4 is a graph showing the effect of charge volume of thecarbohydrazide nitrate of Figure l on velocity.

Broadly, the objects of this invention are accomplished by the use ofcarbohydrazide and/ or semicarbazide-nitric acid-water mixtures with orwithout additives, such as urea, urea mono-nitrate, guanidine nitrate,methanol and benzene.

In one of its aspects the invention may be accomplished by providing aliquid propellant composition consisting essentially of a 100 partcomposition yof about 34 to 64 parts by weight of a substance selected4from the lgroup consisting of semicarbazide and carbohydrazidc, .about25 to 55 parts by weight nitric acid and about 7.5 to 16 parts by weightWater.

A more thorough discussion of the method of making and using thepropellants of this invention can be shown by reference to specificexamples, illustrating preferred techniques.

EXAMPLE I.-SYNTHESIS OF CARBOHYDRAZIDE For every mole of diethylcarbonate used, two moles Vplus some excess of hydrazine in the form ofan 85% hydrazine hydrate solution is used. The mixture is heated anddistilled until the temperature reaches about y120 C. The reaction isthen allowed to cool to enable the carbo- Patented Feb. 7, i961hydrazide to crystallize. The crystals are ltered and dried. A yield ofabout 65-85% is obtained.

The required quantities of carbohydrazide and concentrated nitric acid(70%) were mixed to form the desired ratio by slowly adding the nitricacid to the carbohydrazide. Heat and some slight vaporization of thewater of the nitric acid occurred. The nitrate salts formed were clear,faintly yellow, viscous liquids.

A liquid reaction product made by use of equimolar quantities of thecarbohydrazide and nitric acid was dehydrated by an extraction withethyl alcoholk and then dried over anhydrous magnesium perchlorate in avacuum dessicator at l0 mm. pressure.

An analysis of the resultant dried solution of the mononitrate wasperformed using the Karl Fisher method and the xylene distillationmethod for water determination. The ethyl alcohol content was determinedby distillation of the liquid salt product with water, oxidizing withdichromate and back titrating the dichromate with vferric sulfate. Thepurity of the salt was checked with a nitrate determination. 'Ihepercentages of each ingredient were determined to be (by weight):

Percent Carbohydrazide mononitrate 87.1 Water 10.8 Ethyl alcohol 0.9

The properties of the mono and dinitrate of carbohydrazide in the liquidsalt form are tabulated as follows:

EXAMPLE in sYNTHEsIs 0F sI-:MiCARBAzID- E- Semicarbazide may besynthesized by various techniques as disclosed in C. C. Clark,Hydrazine, tirst edition, 1953, pages 59-61, published by the MathiesonChemical Corporation, Baltimore, Maryland. The method here used involvesthe relluxing of urea and hydrazine hydrate in amyl alcohol according tothe following equation:

Equal molar quantities of urea and hydrazine in the form of an hydrazinehydrate solution are reuxed at 118 C. for several hours. Water isremoved under vacuum until the mixture attains a temperature of C. Themolten semicarbazide is then dissolved in methanol, filtered hot and theliltrate cooled with stirring to precipitate the semicarbazide. Thesemicarbazide is filtered, washed with methanol and dried under vacuum.A yield of 70% semicarbazide melting at 92-95" C. is obtained.

EXAMPLE IV.-SEMCARBAZIDENITRIC ACID-WATER SYSTEM The required quantitiesof semicarbazide and concentrated nitric acid (70%) were mixed to formthe desired ratio by slowly adding the nitric acidj tothe semicarbazide.Heat and slight vaporization of the water of the nitric acid occurred.The nitrate salts formed were clear, faintly green, viscous liquids.

An aqueous salt mixture made by use of equmolar quantities of thesemicarbazide and nitric acid was concentrated by an extraction withethyl alcohol. A simi-` -lar analysis as performed ou the carbohydrazidenitrateV mixture of Example II was performed on the semicarbazidenitrate mixture and gave the following result (by weight):

\ Percent Semicarbazide mononitrate 92.0 Water 7.5 Ethyl alcohol 0.7

These systems were subjected to ballistic tests in their aqueoussolution form with or without additives.

Table II.-Ballistic tests SEMICARBAZIDENITRIC ACID-WATER sYs'rm/iliNitrocellulose 88.3%, dnitrotoluene 8.8%, K2SO4 0.6%, diphenyl amine0.6%.

Table IIL- Ballistic tests CARBOHYDRAZIDE AND SEMICARBAZIDE-NITRIC ACID-WATER SYSTEM System (by Weight) Charge Velocity, Pressure, (cc.) ftJsec.lbs./sq.in. Carbohydrazlde Semicar- Nitric Water bazide Acid 1 Nitrocellulose 88.3%. dinitrotoluene 8.8%, KzSO4 0.6%, diphenylaruinc0.6%.

Ballistic tests Test rings using a carbohydrazide or semicarbazidenitricacid-Water system made by the techinque of Ex? amples II and IV weremade using a commercially available brass cartridge case (-Super X -05caliber) with a centerre primer (Type 257W) (both manufactured by theWestern Cartridge or Winchester Repeating Arms Plants of the OlinMathieson Chemical Corporation of New Haven, Connecticut).l Beforeloading, the flash hole leading from the primer into the main cavity ofthe cartridge was covered with a polyethylene disc prior to seating theprimer. v Y Y Tabulations of the ballistic tests performed for eachsystem are given in Tables I, II and III.

Table 1.-Ballstc tests CARBOHYDRAZIDE-NITRIC ACID-WATER SYSTEM System(by weight) Charge Velocity, Pressure, (cc.) it./sec. lbs/sq. in.Carbohydrazide 1N itric Water Acid 1MB l (control) 50 gr. 2, 600 40, 00051.5 36. 8 10.8 2 1,714. 40, 2G() 35.9 13.0 2 1,792 55, 200 35. 5 14.0 21, 591 41, 500 33. 6 9. 5 2 1, 734 46, 700 31.8 8. 4 2 1, C65 45, 0C()29. 6 7. 9 2 1. 630 44, 600 39. 5 10.5 2 1, 811 56, 200 43.8 11. 6 21,855 59,800 47. 6 12.6 2 1,906 0 600 50. 3 13. 4 2 1, 929 58, 300 49. 015. 6 2 1, 941 65, 300 48. 1 17. 2 2 l, 735 43, 000

lNltrocellulcse 88.3 dinitrotolueue 8.8 KSO 0,6 I -he 1 amineu.%, .'75,2 4 dip ny The systems carbohydrazide-nitric acid-Water andsemicarbazde-nitric acid-water were further studied to determine therange of concentrations which gave no misres under the conditions used.The liquids to be red were prepared by adjusting ethyl alcohol-washedCMN or SMN with the desired amount of water. The amount of alcoholretained by the washed nitrate was less than 1%. Pressures andvelocities were not measured during these rings. Results for 1 cc.charges are plotted onYFigures v1 and 2. The area bounded by the blacklines on each ligure indicates the operable compositions.

In another series of tests under the same conditions the charge volumewas varied from 0.5 cc. to 4 cc. of CMN and the pressure and velocitymeasured. Results are shown on Figures 3 and 4.

In attempting to dehydrate the carbohydrazide mononitrate by lheatingC.), it was found that water was driven off. At the cessation of thiswater evolution, heating was discontinued. The distillate was opaquemilky white and very viscous. Upon standing, it scparated into twophases into a clear, colorless, viscous liquid and the white solid. Itwas found that the solid constituted about 18% of the total weight ofthe distillate. Repeated attempts at analyzing and classifying thissubstance were unsuccessful. It was assumed that the solid material waseither a decomposition product or a product of molecular rearrangementor both.

The white solid behaved as a propellant. This was demonstrated by firingcaliber .30 rounds with a charge containing the solid. Table IV showsthe results.

Table IV.-Test of CMN dehydration product The CMN dehydration productwas found to be in- 3. A liquid propellant composition consistingessensensitive to the impact of a 2 kilogram weight dropped tially of asemicarbazide-nitric-acid-Water mixture as in- 80 centimeters. It couldnot be detonated with a #6 dicated by II of Figure 2 of the drawing.electric blasting cap. 4. The method of developing a projectilepropelling 'The ballistic results shown above were varied to a 5pressure within an enclosed chamber which comprises inmore desirablerange by adding certain additives to the sorting within said chamber aquantity of a composition carbohydrazide and/or semicarbazide-nitricacid-water made up of 100 parts, said composition consisting essystems.The addition was carried out by adding the sentially of about 34 to 64parts by weight of carbohyadditive to the propellant system, mixing itand then drazide about to 55 parts by weight of nitric acid and loadingcartridge cases with the proper amount of the 10 7.5 to 16 parts byweight of water, and locally igniting mixture. A tabulation of thefiring tests is seen in Table said mixture.

V, 5. A method of developing a projectile propelling pres- T ableV.Ballslc tests ADDITIVES To GARBOHYDRAZIDEAIIJIDS/gMSEMIOARBAZIDE-NITRIC ACID-WATER S stem b wei ht) y y g ChargeVelocity, Pressure,

Additives (ce.) itz/sec. lbs/sq. in. Carbohydrazide Semlcar- NitricWater bazide Acid IMR l (control) 50 gr. 2, 600 49, 000 51.5 34. 5 10. 5Urea 2. 6 2 1, 729 54, 000 34. 5 10. 5 Urea mononitrate--- 2. 5 2 1, 82156, 700 33. 6 10. 3 do 4. 8 2 1, 785 52, 700 32. 8 10.0 7. 2 2 1, 79247, 400 32. 0 9. 9 9. 3 2 1, 850 58, 100 34. 5 10.5 2. 7 2 1, 805 56,300 40. 8 7. 2 o 2. 7 2 1, 849 53, 600 35. 7 10. 8 Benzene washed 2 1,767 51, 600 42. 5 7. 5 do 2 1, 766 49, 400

1 Nitrocellulose 88.3%, dinitrotoluene 8.8%, KzSOi 0.6%, dphenylamlne0.6%. Y

As seen n the data above the propellant compositions sure withinanenclosed chamber which comprises inof this invention are aqueoussolutions of carbohydrazide serting within said chamber a compositionmade up of OI SemicarbaZide mOIlO Or dinitrate 01` dehydration pI'Od-100 parts, Said composition containing as its essential UCS OI' theirIliXui'eS With OI Without additives in trace ,ingredients about to partsby Weight 0f a com.. to substantial quantities of the mixture. Theadditives pound selected from the group Consisting of Semmai-ba. n'faYbe Semfafbazid'e cafbohydl'azide urea urea mono' zide andcarbohydrazide, about 25 to 55 parts by weight amate guamdme. nitratePiethmol and 'benzine' .By of nitric acid and about 7.5 to 16 parts byweight of water trace to substantial quantities is meant anythingwithand locally igniting said mixture.

in the range of 0.1% to 10% by weight. A trace 40 6. A method ofdeveloping a proJectile propelling presquantlty generally results fromWashmg of the aqueous sure within an enclosed chamber which comprisesinsertmixture with an additive. .th. .d h b d f 100 While a detaileddescription of this invention has been mg W1 1, sal C fr? er a(forlposmon ma e up o parts, said composition consisting essentially of34 to 64 provided, it is realized that those skilled in the art may makemodications in and adaptations of the propellant Parts by Welght 0fSemlcabazlde, 3h01 25 t0 55 PaI'S composition and its method ofmanufacture described by Weight 0f DTC acid and about 7-5 t0 16 Pal'S byherein without departing from the spirit and scope of this Weight 0fWater and 100311) gHDg Said mXtUIe IO invention. It is, therefore, to bespecifically understood cause a burning of the liquid compositiontherein.

that such obvious modifications are to be considered within the scope ofthe herein described propellant and method of manufacture.

The invention having thus been described what is to be` secured byLetters Patent is as follows:

1. A liquid propellant composition consisting essen tially of a 100 partcomposition of about 34 to 64 parts by weight of a substance selectedvfrom the group con- OTHER REFERENCES sisting of seiriicarbazide andcarbohydrazide, about 25 Thiele et al.: Annalen der Chemie VOL 283, pp22, $1555 bpartelgit vigilt nitric acid and about 7.5 to 16 23. (opy inScientic. Library) I n 2. A liquid propellant composition consistingessentially & ndnetlh' Tg? ChnultryNcg. Hggzme Jogs Wllilesy of acarbohydrazide-nitric-acid-water mixture as indons? ncl .ew or pp catedby '1 of Figure 1 of the drawing. (COPY m Scl- L12) References Cited inthe tile of this patent UNITED STATES PATENTS Whetstone et al. Nov. 30,1948 Hutchison June 29, 1954

6. A METHOD OF DEVELOPING A PROJECTILE PROPELLING PRESSURE WITHIN ANENCLOSED CHAMBER WHICH COMPRISES INSERTING WITHIN SAID CHAMBER ACOMPOSITION MADE UP TO 100 PARTS, SAID COMPOSITION CONSISTINGESSENTIALLY OF 34 TO 64 PARTS BY WEIGHT OF SEMICARBAZIDE, ABOUT 25 TO 55PARTS BY WEIGHT OF NITRIC ACID AND ABOUT 7.5 TO 16 PARTS BY WEIGHT OFWATER AND LOCALLY IGNITING SAID MIXTURE TO CAUSE A BURNING OF THE LIQUIDCOMPOSITION THEREIN.